I've just discovered a crack right across the "off side" clamp that holds the front wheel on. To inspect Park your bike and check with a bright light and a big magnifer...unless you've got perfect eyes. You need to lay with you head under the wheel each side. My brother thought it was writing to start with, but upon closer inspection we found a visible crack across the shear line below the pinch bolts over externally visible 60% through the whole width. <later correction on the inside it's 100% cracked> 100% would have meant a total front wheel lock up!!!. Checking the torque the bolts were hand tight (as you'd expect given the crack), the other side was easily undone with a 6" allen key. I don't think these bolts were over tightened, however to ensure a complete picture the front tyre was changed just 800 miles ago. So the whole story. June 2010 MTS1200 S with Ohlins semi-active suspension. 23,000 miles. Bike hand cleaned, no horrible chemicals... Fork part numbers are O/S FG860 manufacturered 4/2/2010 N/S FG860 manufacturered 5/2/2010 Note these numbers can be found on the inside of the fork foot/casting, only visible once you remove the wheel, as the disks hide the text. I think it's going to be a week or so to turn them around. Photo's and a full price breakdown for the repair to follow. Note the o/s fork casting that holds the front spindle is only 5.5mm thick the other side is twice as thick. This may explain why that side failed. I've standard spindles so I can't see why this should happen. Please check your bike today...this would be an' orrible way to crash your 'strada and possibly end your life. By the way I was only checking the forks at this point looking for a part number so I could order the correct tool to change the fork springs...I can't beleive how lucky I've been. I feel sick now I've actually seen how bad it is with no symptoms!
this does tie in with some posts on another Forum showing stress cracks around front caliper mounts - it was an early version of strut apparently and replaced under warranty. I can't remember which Ducati but it was within last 4 years and it was Ohlins. http://www.ducati.ms/forums/56-superbikes/67305-ohlins-fork-recall-picture.html http://www.ducati.ms/forums/138-streetfighter/71065-another-fn-fork-recall.html I can't believe Ohlins are still sailing so close to the wind - above incidents should have been a big enough wake-up call considering the possible consequences.
I would also get Ducati involved as they may require part analysis. They may cover your costs and if its a manufacturing defect and issue relevant notices.
Thank you all for the positive comments. FTR will return all the parts to me. We are in the process of packing both forks. FTR Suspension seem very reasonable with their charges and the service promised appears great. All prices approx and plus VAT Insured collection and delivery £40 Replacement casting/foot £203 Labour £100 Suspension Oil cost unknown, but extra. They will install my uprated front springs at the same time, servicing and then replacing the suspension oil (cost to be advised). I'll get in touch with the Ducati dealer who sold the machine and will keep you informed.
Reply to Oneball. I've checked it again and no, not an indentation. It's a camera and lighting angle thing. It's a change in direction for the crack and it corresponds to the thicker part of the casting on the split centre line for the cast. See the outside of the fork image. Note the crack is side to side from the inside and now over 80% on the outside (us wiggling the spindle out). I would love an opinion from an engineer or similar.
Gorilla like over tightening at some point? . A good spot and something to keep an eye on all fork bottom. A fantic motor enduro bike I had many years ago had the same fault, resultant from zealous over tightening (operator error - me)
It was not over tightened last time. Hand tight 5-6" small bondus lever, small mount of thread lock. I've had a very expensive experience with White Power front forks a few years ago. Eventually traced to an undersized spindle, custom made, also supplied by White Power. I paid once and they paid the second time. Good company, given that the forks were about 4 years old when they failed.
Please can someone tell me where else I should post my warning? Sensible suggestions only please...I'm not in the mood...still shaking and feeling sick.
You'd ideally need it in two pieces so you could examine the failure surface, most of it is likely to be indicative of fatigue caused after an initial failure weakened the structure. When you can identify the initial failure point then you'll start to get some idea of the cause. Assuming the part didn't fail due to a design issue, the two most likely causes are over tightening of the clamp or a manufacturing fault such as an inclusion.
Get Matt to make it a sticky And I'm sure he won't mind you pasting in lounge and technical or where you may want too
I'm sure this got covered before, a couple of years ago? Warranty replacements? The tightening torque is tiny (15Nm IIRC) and you have to use a 1-2-1-2 pattern when tightening.
after a quick read-up and to be fair to Ohlins although they did put their hand up to a faulty casting affecting Street fighters around 2010 in the past, operator error is possible here (not suggesting you AirCon) as Cranker suggested and correct tightening procedure of these clamp bolts (e.g. - dry or lubricated for instance) is obviously crucial on this design of axle clamp.
I'm supposed to be an engineer but my skills lie in the direction of high speed rotating equipment so all I can do is make a semi-educated guess.... It looks like a casting defect but the only way to be sure of it is to split the casting completely and I'd strongly advise against doing that. If it was down to you over tightening it then the crack line would be a lot straighter but it's followed a line of weakness in the casting. I think you should send it to Ducati so they can have a look at it and they'll almost certainly send it on to Ohlins. I'd be shocked if you didn't get a new casting out of them but you may struggle to recover labour costs from them. Whichever way you go they'll want all parts so budget for a new spindle as well if you want it back on the road asap. If you want to avoid sending the spindle anywhere then ask FTR to give you an inspection report giving the sizes of the spindle so you can remove that from the equation. Good luck.
I have a Mito yoke that the previous owner owned up to overtightening - it's a similar example of the material yielding and it certainly isn't cracked in any straighter manner than above fork clamp. And just to repeat, it could have been a previous owner who had already weakened the area.
Ohlins give out warnings about over-tightening the pinch bolts and making sure they are done up in the correct way and order. Its a common problem.
Just to clarify something; it will have been caused by tightening it but it looks as if there was a defect there which made it crack more easily than it should. Ducati might try to argue that you did it by over tightening but tell them you've always tightened them sequentially and used a torque wrench to do it when you've had the wheel out.
